Air compressor



FIG. 1 is a first perspective view of an ornamental design for an air compressor showing my new design in a position of use with a handle;

FIG. 2 is a second perspective view of an ornamental design for an air compressor;

FIG. 3 is an opposite side view to that shown in FIGS. 1 and 2;

FIG. 4 is a side view of an ornamental design for an air compressor; and,

FIG. 5 is a top view of an ornamental design for an air compressor.

It being understood that the broken lines are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for an air compressor, as shown and described. 